Lighting devices are often connected to dimmers (light control units) to provide control over the intensity of light emitted from the lighting devices. When light intensity is to be adjusted, a light control unit typically receives a (relative) light input level. This input is frequently in terms of a light level percentage of a maximum light level. This (relative) light input level is then converted into an analogue control voltage by the light control unit. The control unit utilizes a linear approximation of a dim curve, generally expressed as y=ax+b, where y is the relative light level, x is the control voltage, and a and b are constant values, to determine the control voltage that matches the received light input level. To establish this linear approximation, the light control unit typically derives parameters defining e.g. slope and intersection with the y axis from predetermined data in a “lamp type file”. The linear approximation is generally made such as to match the driver dim curve as closely as possible. The analogue control voltage derived from the above mentioned approximation is converted into a (relative) light output level by the dimming driver and lamp of the lighting device.